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| math [2019/07/04 20:43] – [AnglesToVector] korshun | math [2019/08/26 21:16] – korshun |
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| ''int ipow(int x, int y)'' | ''int ipow(int x, int y)'' |
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| Returns x^y. Uses a simple multiplication loop. | Returns x<sup>y</sup>. Uses a simple multiplication loop. |
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| ==== fpow ==== | ==== fpow ==== |
| ''fixed fpow(fixed x, fixed y)'' | ''fixed fpow(fixed x, fixed y)'' |
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| returns x^y. Supports powers below ''1.0''. Uses a simple loop with ''FixedMul'' or ''FixedDiv'', depending on whether the power is below ''1.0''. | returns x<sup>y</sup>. Supports powers below ''1.0''. Uses a simple loop with ''FixedMul'' or ''FixedDiv'', depending on whether the power is below ''1.0''. |
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| ===== Vector math ===== | ===== Vector math ===== |
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| ==== VectorLength3D ==== | ==== Length ==== |
| ''fixed VectorLength3D(fixed x, fixed y, fixed z)'' | |
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| A 3D version of [[zdoom>VectorLength]]. Returns the length of the 3D vector. | * 2D: [[zdoom>VectorLength]] |
| | * 3D: ''fixed VectorLength3D(fixed x, fixed y, fixed Z)'' |
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| | ''VectorLength3D'' is implemented efficiently as ''VectorLength(VectorLength(x, y), z)''. |
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| | ==== Dot product ==== |
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| ==== dot ==== | |
| * 2D: ''fixed dot2(fixed x1, fixed y1, fixed x2, fixed y2)'' | * 2D: ''fixed dot2(fixed x1, fixed y1, fixed x2, fixed y2)'' |
| * 3D: ''fixed dot3(fixed x1, fixed y1, fixed z1, fixed x2, fixed y2, fixed z2)'' | * 3D: ''fixed dot3(fixed x1, fixed y1, fixed z1, fixed x2, fixed y2, fixed z2)'' |
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| Returns the [[wp>dot product]] of two vectors. Shorthand for writing out ''FixedMul(x1, x2) + FixedMul(y1, y2) + ...''. | These functions return the [[wp>dot product]] of two vectors. They are shorthands for writing out ''FixedMul(x1, x2) + FixedMul(y1, y2) + ...''. |
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| | ==== Normalization ==== |
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| ==== normalize ==== | |
| * 2D: ''fixed, fixed normalize2d(fixed x, fixed y)'' | * 2D: ''fixed, fixed normalize2d(fixed x, fixed y)'' |
| * 3D: ''fixed, fixed, fixed normalize3d(fixed x, fixed y, fixed z)'' | * 3D: ''fixed, fixed, fixed normalize3d(fixed x, fixed y, fixed z)'' |
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| [[wp>Normalized vector|Normalizes]] the vector and returns the result using [[multiple return values]]. | These functions [[wp>Normalized vector|Normalize]] the input vector and return the result using [[multiple return values]]. |
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| === Example usage === | === Example usage === |
| Converts the vector's direction to a pair of angles (angle, pitch) and returns them using [[multiple return values]]. | Converts the vector's direction to a pair of angles (angle, pitch) and returns them using [[multiple return values]]. |
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| <note important>Remember that ZDoom uses inverted pitch angles on actors. ACSUtils functions don't invert pitches.</note> | <note important>Remember that ZDoom uses negated pitch angles on actors. ACSUtils functions don't use negated pitches. </note> |
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| === Example usage === | === Example usage === |
| int pitch = r2; | int pitch = r2; |
| SetActorAngle(tid, angle); | SetActorAngle(tid, angle); |
| SetActorPitch(tid, -pitch); // SetActorPitch expects inverted pitch. | SetActorPitch(tid, -pitch); // SetActorPitch expects negated pitch. |
| } | } |
| </code> | </code> |
| Converts a pair of angles (angle, pitch) to a 3D vector of length ''1.0'', which points in the same direction, and returns it using [[multiple return values]]. | Converts a pair of angles (angle, pitch) to a 3D vector of length ''1.0'', which points in the same direction, and returns it using [[multiple return values]]. |
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| <note important>Remember that ZDoom uses inverted pitches on actors. ACSUtils functions don't invert pitches.</note> | <note important>Remember that ZDoom uses negated pitch angles on actors. ACSUtils functions don't use negated pitches.</note> |
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| === Example === | === Example usage === |
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| <code> | <code> |
| AnglesToVector(GetActorAngle(0), -GetActorPitch(0)); | AnglesToVector(GetActorAngle(0), -GetActorPitch(0)); // Un-negate actor pitch |
| int dirX = r1; | int dirX = r1; |
| int dirY = r2; | int dirY = r2; |
